“We’re treading on mushrooms everywhere in the UK, unless you’re stood on tarmac.

“There are mushrooms probably growing underground on 75% of the UK’s woodland.

“Those mushrooms don’t always fruit, but when they are growing underground and they reach a nutrient boundary like a road or a car park they can’t grow any further underground in that direction so they fruit more to try and cross that neutral boundary.”

Foraging has come a long way since I picked blackberries as a child in rural West Wales.

According to Mr Biggane, the revolution began in Copenhagen and the world restaurant of the year, Noma, which relies entirely on foraged food.

Its success has set a trend in the restaurant trade.

But the recession has also increased interest.

Next page: Finding food in the wild

“In all honesty I don’t think many people could afford to eat some of the things that we find in the wild, things growing in this park in Cardiff,” said Mr Renton.

Foraging is not without its dangers – as Mr Renton demonstrates with one leaf.

“This is an interesting one,” he said.

“It’s wild chervil, a plant related to the carrot family or umbelliferae.

“The carrot family is really interesting to foragers because it has some of the best plants to eat.

“Umbelliferae also has some of the deadliest plants in the country.

“If you are a novice forager this is a plant that you would take very great caution in picking.

“Hemlock, for example, looks very similar to wild chervil but is deadly poisonous.

“It was the poison which Socrates chose for his execution.

“Hemlock water dropwort, which again looks very similar, is even more dangerous.

“If you ate a good mouthful of that, which could be found in parks like this one, it would kill you before you had time to get to hospital.

“If you don’t know what it is don’t eat it.

“If you’re an interested novice get involved with something like we’re offering here, or learn the basics, then take it on yourself.

“You start off not knowing what some mushrooms are so you leave them.

“So you learn what they are and next time you know if you can eat them or leave them.”

There are also written rules about foraging which novices should be aware of.

Adhering to the Countryside Act means you are basically aloud to pick the “four Fs”, fruit, flowers, fungi and foliage.

Mr Biggane said: “You can’t dig up roots, you are only allowed to pick from common land or public places for your own personal use.”

But, Mr Renton adds: “The fact is though that there is free food on all our doorsteps and with a little education anybody can enjoy it.”

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